1. Field of the Invention
The present invention relates to a method for taking out a workpiece by using a robot including holding fingers.
2. Description of the Related Art
Conventionally, a technique of using holding fingers provided in a robot hand for taking out a plurality of workpieces close to one another, one after another, by using a robot is well known. For example, in Japanese Unexamined Patent Publication No. 9-103983 disclosing fingers for a robot hand, there is the description “each of fingertip parts 4 of finger forming bodies 1 configured so as to be switchable between a hold posture and a hold-releasing posture is formed of a soft material that has a cylindrical shape in which a base end portion is open, and a free end portion is closed. A back portion 4a and a belly portion 4b of each fingertip part 4 are formed so as to be flat. A separate distance between the back portion 4a and the belly portion 4b of each fingertip part 4 is set in a state in which the back portion 4a and the belly portion 4b are positioned almost on each other. Then, in the hold-releasing posture, the fingertip parts 4 can be inserted into narrow spaces on the lateral sides of a holding target object. In the inserted state, fluid from a fluid supplying unit 3 is supplied to the insides of the fingertip parts 4 so that the back portions 4a and the belly portions 4b can be inflated to be separated from each other. Thereby, in the holding posture, the belly portions 4b are pressed against the holding target object to hold the holding target object”.
It is understood that according to the technique of Japanese Unexamined Patent Publication 9-103983, after the fingertip parts formed of the cylindrical soft material are inserted into the narrow spaces on the lateral sides of the holding target object, fluid is then supplied to the insides of the fingertip parts to inflate the fingertip parts, and the fingertip parts thereby hold the holding target object. However, when holding means is formed of the soft material as described above, it can become difficult to accurately and securely hold a target object.
Therefore, an object of the present invention is to provide a workpiece taking-out method that can easily and accurately take out workpieces close to one another, one after another even when rigid holding fingers are used.